Inhibitory effects of thought substitution in the think/no-think task: evidence from independent cues

Everything you ever wanted to know about the Think/No-Think task, but forgot to ask

The Think/No-Think (TNT) task has just celebrated 20 years since its inception, and its use has been growing as a tool to investigate the mechanisms underlying memory control and its neural underpinnings. Here, we present a theoretical and practical guide for designing, implementing, and running TNT studies. For this purpose, we provide a step-by-step description of the structure of the TNT task, methodological choices that can be made, parameters that can be chosen, instruments available, aspects to be aware of, systematic information about how to run a study and analyze the data. Importantly, we provide a TNT training package (as Supplementary Material), that is, a series of multimedia materials (e.g., tutorial videos, informative HTML pages, MATLAB code to run experiments, questionnaires, scoring sheets, etc.) to complement this method paper and facilitate a deeper understanding of the TNT task, its rationale, and how to set it up in practice. Given the recent discussion about the replication crisis in the behavioral sciences, we hope that this contribution will increase standardization, reliability, and replicability across laboratories.

Suppression-induced forgetting: a pre-registered replication of the think/no-think paradigm

Post-traumatic stress disorder is characterised by recurring memories of a traumatic experience despite deliberate attempts to forget (i.e., suppression). The Think/No-Think (TNT) task has been used widely in the laboratory to study suppression-induced forgetting. During the task, participants learn a series of cue-target word pairs. Subsequently, they are presented with a subset of the cue words and are instructed to think (respond items) or not think about the corresponding target (suppression items). Baseline items are not shown during this phase. Successful suppression-induced forgetting is indicated by the reduced recall of suppression compared to baseline items in recall tests using either the same or different cues than originally studied (i.e., same- and independent-probe tests, respectively). The current replication was a pre-registered collaborative effort to evaluate an online experimenter-present version of the paradigm in 150 English-speaking healthy individuals (89 females; MAge = 31.14, SDAge = 7.73). Overall, we did not replicate the suppression-induced forgetting effect (same-probe: BF01 = 7.84; d = 0.03 [95% CI: -0.13; 0.20]; independent-probe: BF01 = 5.71; d = 0.06 [95% CI: -0.12; 0.24]). These null results should be considered in light of our online implementation of the paradigm. Nevertheless, our findings call into question the robustness of suppression-induced forgetting.

EXPRESS: "Be careful what you recall": Retrieval induced forgetting of genuine real-life autobiographical memories

Which episodes from our lives will be remembered and which will be forgotten, and why? This question has still not been answered satisfactorily by research into autobiographical memory. Previous work has shown that retrieval-induced forgetting (RIF) might be a factor responsible for forgetting parts of the autobiographical memory content. However, none of the previous studies assessed RIF in memories for recent, controlled, personal events. We report here the results of an experiment in which autobiographical memories of real-life events were induced in a controlled, but fully naturalistic, manner, under the disguise of team-building exercises, while an adapted RIF paradigm was applied to these memories. Results clearly showed the influence of RIF on auto-biographical memory retrieval. These findings demonstrate conclusively that RIF occurs in everyday life when remembering personal events.

Memory Control: A Fundamental Mechanism of Emotion Regulation

Memories play a ubiquitous role in our emotional lives, both causing vivid emotional experiences in their own right and imbuing perception of the external world with emotional significance. Controlling the emotional impact of memories therefore poses a major emotion-regulation challenge, suggesting that there might be a hitherto unexplored link between the neurocognitive mechanisms underlying memory control (MC) and emotion regulation. We present here a theoretical account of how the mechanisms of MC constitute core component processes of cognitive emotion regulation (CER), and how this observation may help to understand its basic mechanisms and their disruption in psychiatric disorders.

Mnemonic emotion regulation: a three-process model

Emotion regulation comprises attempts to influence when and how emotions are experienced and expressed. It has mostly been conceived of as proactive (e.g. situation selection) or reactive (e.g. attentional distraction), but it may also be retroactive and involve memory. I term such past-oriented activity mnemonic emotion regulation and propose that it involves increasing or decreasing access to or altering the characteristics of a memory. People may increase access to a memory and make it more likely that it will be retrieved in the future, for example by rehearsing a pleasant memory. They may decrease access to a memory and make it less likely that intrusions will be experienced in the future, for example by repeatedly trying to stop an unpleasant memory from being retrieved. Finally, people may alter the characteristics of a memory and change its content or context, for example by replacing a negative impression with a productive interpretation. I discuss how mnemonic emotion regulation may be instigated (e.g. via elaborate rehearsal) as well as the different motives (e.g. hedonic motives) people may have for engaging in regulation. Also, I discuss possible benefits of, variations in, and improvements of mnemonic emotion regulation.

The Role of Cognitive Load in Intentional Forgetting Using the Think/No-Think Task

Abstract. We investigated the role of cognitive control in intentional forgetting by manipulating working memory load during the think/no-think task. In two experiments, participants learned a series of cue-target word pairs and were asked to recall the target words associated with some cues or to avoid thinking about the target associated with other cues. In addition to this, participants also performed a modified version of the n-back task which required them to respond to the identity of a single target letter present in the currently presented cue word (n = 0 condition, low working memory load), and in either the previous cue word (n = 1 condition, high working memory load, Experiment 1) or the cue word presented two trials previously (n = 2 condition, high working memory load, Experiment 2). Participants’ memory for the target words was subsequently tested using same and novel independent probes. In both experiments it was found that although participants were successful at forgetting on both the same and independent-probe tests in the low working memory load condition, they were only successful at forgetting on the same-probe test in the high working memory load condition. We argue that our findings suggest that the high load working memory task diverted attention from direct suppression and acted as an interference-based strategy. Thus, when cognitive resources are limited participants can switch between the strategies they use to prevent unwanted memories from coming to mind.

Intentional forgetting in dysphoria: Investigating the inhibitory effects of thought substitution using independent cues

BACKGROUND

Individuals with clinical and subclinical depression (dysphoria) exhibit problems intentionally forgetting unwanted memories on the think/no-think (TNT) paradigm (Anderson & Green, 2001). However, providing substitute words to think about instead of the to-be-forgotten targets can improve forgetting in depressed patients.

OBJECTIVES

To determine if thought substitution can enhance forgetting in dysphoric participants and to examine the potential mechanisms (blocking or inhibition) that might underpin successful forgetting.

METHODS

Thirty-six dysphoric and 36 non-dysphoric participants learned neutral word-pairs and then practiced responding with the targets to some cues (think trials) and suppressing responses to others (no think trials). Half the participants were provided with substitute words to recall instead of the original targets (aided suppression) and half were simply told to avoid thinking about the targets (unaided suppression). Finally, participants completed two recall tests for the targets; one cued with the original probes and one with independent probes.

RESULTS

Regardless of suppression condition (aided or unaided), dysphoric participants exhibited impaired forgetting, relative to their non-dysphoric counterparts, but only when cued with the original probes. Furthermore, higher depression scores were associated with poorer forgetting. In the aided condition, successful forgetting was observed on both the original and independent probe tasks, which supports the inhibitory account of thought substitution.

LIMITATIONS

Non-clinical status of the dysphoric participants was not confirmed using a validated measure.

CONCLUSIONS

Findings do not support the utility of thought substitution as a method of improving the forgetting in depressed participants, but do support the inhibition account of thought substitution.

Examining the impact of thought substitution on intentional forgetting in induced and naturally occurring dysphoria

Two experiments were conducted to determine if natural and induced dysphoria is associated with impaired forgetting and, whether a thought-substitution strategy would ameliorate any observed deficits. Study 1: 36 dysphoric & 36 non-dysphoric participants learnt a series of emotional word pairs. Participants were subsequently presented with some of the cues and were asked to recall the targets or prevent the targets from coming to mind. Half of the participants were provided with substitute words to recall instead of the original targets (aided suppression). At final memory testing, participants were asked to recall the targets to all cues. Dysphoric participants exhibited impaired forgetting, even when using a thought substitution strategy. Non-dysphoric participants, however, were able to use substitutes to suppress words. Study 2: 50 healthy participants initially completed the aided condition of the forgetting task. Participants were then given a positive or negative mood-induction, followed by another version of the forgetting task. Although all participants showed a forgetting effect prior to the mood-induction, only the positive group was successful at forgetting after the mood induction. Taken together, these findings do not support the utility of thought-substitution as an aid to forgetting in individuals in a naturally or induced dysphoric mood.